Almost nine out of every 10 Americans who are looking for private health insurance never buy a plan, and one in five who applies turned down or charged more because of preexisting conditions, a new report finds.

In addition, two out of five who purchased private plans with high deductibles later discovered that some of their medical costs were not covered by their particular plan, according to data released Thursday by the non-profit group The Commonwealth Fund.

The report comes at a time when the number of uninsured Americans is at an unsurpassed high. A record-setting 46.6 million Americans, or 15.9 percent, were without heath insurance in 2005, up from 45.3 million, or 15.6 percent, in 2004, according to new U.S. Census Bureau figures.